138749928 has 16 divisors (see below), whose sum is σ = 346874880. Its totient is φ = 46249968.

The previous prime is 138749921. The next prime is 138749953. The reversal of 138749928 is 829947831.

It is not an unprimeable number, because it can be changed into a prime (138749921) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2890600 + ... + 2890647.

It is an arithmetic number, because the mean of its divisors is an integer number (21679680).

Almost surely, 2^138749928 is an apocalyptic number.

It is an amenable number.

138749928 is an abundant number, since it is smaller than the sum of its proper divisors (208124952).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

138749928 is a wasteful number, since it uses less digits than its factorization.

138749928 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5781256 (or 5781252 counting only the distinct ones).

The product of its digits is 870912, while the sum is 51.

The square root of 138749928 is about 11779.2159331596. The cubic root of 138749928 is about 517.6993131762.

It can be divided in two parts, 1387 and 49928, that added together give a palindrome (51315).

The spelling of 138749928 in words is "one hundred thirty-eight million, seven hundred forty-nine thousand, nine hundred twenty-eight".